Sure. There are a few local projects along these lines, with limited success. See freifunk.net, for example. The main problem is that the range of WiFi is quite

Sure. There are a few local projects along these lines, with limited success. See freifunk.net, for example. The main problem is that the range of WiFi is quite short even in denser urban areas (so you wind up with lots of fragmented micro-networks), and it requires significant effort from each participant to set up. If Fon started making this an optional feature on their routers, it could get really interesting. Or maybe just a way of connecting Android phones into a local communication network. Does anyone know if there's some formal spec for this kind of mesh network?